To improve the performance of yeast cell factories for industrial production,extensive CRISPR-mediated genome editing systems have been applied by artificially creating double-strand breaks(DSBs)to introduce mutations...To improve the performance of yeast cell factories for industrial production,extensive CRISPR-mediated genome editing systems have been applied by artificially creating double-strand breaks(DSBs)to introduce mutations with the assistance of intracellular DSB repair.Diverse strategies of DSB repair are required to meet various demands,including precise editing or random editing with customized gRNAs or a gRNA library.Although most yeasts remodeling techniques have shown rewarding performance in laboratory verification,industrial yeast strain manipulation relies only on very limited strategies.Here,we comprehensively reviewed the molecular mechanisms underlying recent industrial applications to provide new insights into DSB cleavage and repair pathways in both Saccharomyces cerevisiae and other unconventional yeast species.The discussion of DSB repair covers the most frequently used homologous recombination(HR)and nonhomologous end joining(NHEJ)strategies to the less well-studied illegitimate recombination(IR)pathways,such as single-strand annealing(SSA)and microhomology-mediated end joining(MMEJ).Various CRISPR-based genome editing tools and corresponding gene editing efficiencies are described.Finally,we summarize recently developed CRISPR-based strategies that use optimized DSB repair for genome-scale editing,providing a direction for further development of yeast genome editing.展开更多
Richard Jefferies presented one tragedy after another in a small and backward village in 19th England in his short story Acorn-gatherer.The paper explored the fundamental cause of those tragedies and drew a conclusion...Richard Jefferies presented one tragedy after another in a small and backward village in 19th England in his short story Acorn-gatherer.The paper explored the fundamental cause of those tragedies and drew a conclusion all those tragedies were the expression of human tragedy resulted from social conventions in the form of religion and the tragedy was actually a comedy for the little boy who was just the symbol of human tragedy in the story due to his special identity:an illegitimate child.展开更多
γ-Gliadins are an important component of wheat seed storage proteins. Four novel γ-gliadin genes （Gli-ngl to Gli-ng4） were cloned from wheat （Triticum aestivum） and Aegilops species. The novel γ-gliadins were m...γ-Gliadins are an important component of wheat seed storage proteins. Four novel γ-gliadin genes （Gli-ngl to Gli-ng4） were cloned from wheat （Triticum aestivum） and Aegilops species. The novel γ-gliadins were much smaller in molecular size when compared to the typical γ-gliadins, which was caused by deletion of the non-repetitive domain, glutamine-rich region, 3＂ part of the repetitive domain, and 5＇ part of the C-terminal, possibly due to illegitimate recombination between the repetitive domain and the C-terminal. As a result, Gli-ngl and Gli-ng4 only contained two and three cysteine residues, respectively. Gli-ngl, as the representative of novel γ-gliadin genes, has been sub-cloned into an Escherichia coli expression system. SDS- PAGE indicated that the both cysteine residues of Gli-ngl could participate in the formation of intermolecular disulphide bonds in vitro. Successful cloning of Gli-ngl from seed cDNA of T. aestivum cv. Chinese Spring suggested that these novel γ-gliadin genes were normally transcribed during the development of seeds. Phylogenic analysis indicated that the four novel γ-gliadin genes had a closer relationship with those from the B （S） genome of wheat.展开更多
Flowering plant （angiosperm） genomes are exceptional in their variability with respect to genome size, ploidy, chromosome number, gene content, and gene arrangement. Gene movement, although observed in some of the e...Flowering plant （angiosperm） genomes are exceptional in their variability with respect to genome size, ploidy, chromosome number, gene content, and gene arrangement. Gene movement, although observed in some of the earliest plant genome comparisons, has been relatively underinvestigated. We present here- in a description of several interesting properties of plant gene and genome structure that are pertinent to the successful movement of a gene to a new location. These considerations lead us to propose a model that can explain the frequent success of plant gene mobility, namely that Small Insulated Genes Move Around （SlGMAR）. The SIGMAR model is then compared with known processes for gene mobilization, and predic- tions of the SIGMAR model are formulated to encourage future experimentation. The overall results indicate that the frequent gene movement in angiosperm genomes is partly an outcome of the unusual properties of angiosperm genes, especially their small size and insulation from epigenetic silencing.展开更多
Aims in heterantherous plants,‘division of labor’among structurally dif-ferent stamens,i.e.pollinating and feeding functions,has been thought to reduce the evolutionary conflict of relying on pollen both as the carr...Aims in heterantherous plants,‘division of labor’among structurally dif-ferent stamens,i.e.pollinating and feeding functions,has been thought to reduce the evolutionary conflict of relying on pollen both as the carrier of male gametes and as the food for pollinators.The key to successful division of labor among different sets of stamens is the size match between stamens and legitimate pollinators,which results in the precise deposition of pollen onto specific locations on pollinator’s body and facilitates cross pollination.However,the potential impact of small illegitimate insects that are ubiquitous dur-ing the pollination process on the plant reproduction in heteranth-erous species has been largely neglected in previous studies and never been demonstrated experimentally.Methods Here,we investigated the functions of three different types of sta-mens in Commelina communis.The pollinator visitation,pollen removal and deposition were compared among flowers with dif-ferent types of anthers emasculated at two natural populations.moreover,the mating systems of C.communis in wild populations were estimated using microsatellite markers.Important Findingsour data showed that the main floral visitors for C.communis at the two studied populations were small illegitimate bees rather than legitimate pollinators,accounting for 77.5 and 92.2%of total flower visits,respectively.Flower manipulations in C.communis demon-strated that the two types of brightly yellow stamens separately func-tioned as‘deceptive attraction’and‘feeding’functions.although the brown inconspicuous stamens of C.communis with the largest amount of fertile pollen had the potential function in offering pollen for cross pollination,the high ratio of illegitimate visitation by small bees significantly affected the dispersal and deposition of pollen from the pollinating anthers,and subsequently decreased the levels of outcrossing(tm=0.23-0.32)in wild populations.our work further confirmed that the size match between pollinators and the floral morp展开更多
THE West saw The Hague Arbitral Tribunal＇s arbitration of the South China Sea dispute as an important crossroads in China＇s rise as a global power. The first misperception of the West is that China is rising - it is...THE West saw The Hague Arbitral Tribunal＇s arbitration of the South China Sea dispute as an important crossroads in China＇s rise as a global power. The first misperception of the West is that China is rising - it is not rising, it has already risen, China is actually 10 steps ahead of the West in most cases, and Shanghai makes New York look like the old world.展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFC2101203)the General project of National Natural Science Foundation of China(No.22078021).
文摘To improve the performance of yeast cell factories for industrial production,extensive CRISPR-mediated genome editing systems have been applied by artificially creating double-strand breaks(DSBs)to introduce mutations with the assistance of intracellular DSB repair.Diverse strategies of DSB repair are required to meet various demands,including precise editing or random editing with customized gRNAs or a gRNA library.Although most yeasts remodeling techniques have shown rewarding performance in laboratory verification,industrial yeast strain manipulation relies only on very limited strategies.Here,we comprehensively reviewed the molecular mechanisms underlying recent industrial applications to provide new insights into DSB cleavage and repair pathways in both Saccharomyces cerevisiae and other unconventional yeast species.The discussion of DSB repair covers the most frequently used homologous recombination(HR)and nonhomologous end joining(NHEJ)strategies to the less well-studied illegitimate recombination(IR)pathways,such as single-strand annealing(SSA)and microhomology-mediated end joining(MMEJ).Various CRISPR-based genome editing tools and corresponding gene editing efficiencies are described.Finally,we summarize recently developed CRISPR-based strategies that use optimized DSB repair for genome-scale editing,providing a direction for further development of yeast genome editing.
文摘Richard Jefferies presented one tragedy after another in a small and backward village in 19th England in his short story Acorn-gatherer.The paper explored the fundamental cause of those tragedies and drew a conclusion all those tragedies were the expression of human tragedy resulted from social conventions in the form of religion and the tragedy was actually a comedy for the little boy who was just the symbol of human tragedy in the story due to his special identity:an illegitimate child.
基金finically supported by the National Natural Science Foundation of China (31230053)
文摘γ-Gliadins are an important component of wheat seed storage proteins. Four novel γ-gliadin genes （Gli-ngl to Gli-ng4） were cloned from wheat （Triticum aestivum） and Aegilops species. The novel γ-gliadins were much smaller in molecular size when compared to the typical γ-gliadins, which was caused by deletion of the non-repetitive domain, glutamine-rich region, 3＂ part of the repetitive domain, and 5＇ part of the C-terminal, possibly due to illegitimate recombination between the repetitive domain and the C-terminal. As a result, Gli-ngl and Gli-ng4 only contained two and three cysteine residues, respectively. Gli-ngl, as the representative of novel γ-gliadin genes, has been sub-cloned into an Escherichia coli expression system. SDS- PAGE indicated that the both cysteine residues of Gli-ngl could participate in the formation of intermolecular disulphide bonds in vitro. Successful cloning of Gli-ngl from seed cDNA of T. aestivum cv. Chinese Spring suggested that these novel γ-gliadin genes were normally transcribed during the development of seeds. Phylogenic analysis indicated that the four novel γ-gliadin genes had a closer relationship with those from the B （S） genome of wheat.
文摘Flowering plant （angiosperm） genomes are exceptional in their variability with respect to genome size, ploidy, chromosome number, gene content, and gene arrangement. Gene movement, although observed in some of the earliest plant genome comparisons, has been relatively underinvestigated. We present here- in a description of several interesting properties of plant gene and genome structure that are pertinent to the successful movement of a gene to a new location. These considerations lead us to propose a model that can explain the frequent success of plant gene mobility, namely that Small Insulated Genes Move Around （SlGMAR）. The SIGMAR model is then compared with known processes for gene mobilization, and predic- tions of the SIGMAR model are formulated to encourage future experimentation. The overall results indicate that the frequent gene movement in angiosperm genomes is partly an outcome of the unusual properties of angiosperm genes, especially their small size and insulation from epigenetic silencing.
基金Postdoctoral Science Foundation of Central South University(502080023)National Science Foundation of China(31000106,31100173).
文摘Aims in heterantherous plants,‘division of labor’among structurally dif-ferent stamens,i.e.pollinating and feeding functions,has been thought to reduce the evolutionary conflict of relying on pollen both as the carrier of male gametes and as the food for pollinators.The key to successful division of labor among different sets of stamens is the size match between stamens and legitimate pollinators,which results in the precise deposition of pollen onto specific locations on pollinator’s body and facilitates cross pollination.However,the potential impact of small illegitimate insects that are ubiquitous dur-ing the pollination process on the plant reproduction in heteranth-erous species has been largely neglected in previous studies and never been demonstrated experimentally.Methods Here,we investigated the functions of three different types of sta-mens in Commelina communis.The pollinator visitation,pollen removal and deposition were compared among flowers with dif-ferent types of anthers emasculated at two natural populations.moreover,the mating systems of C.communis in wild populations were estimated using microsatellite markers.Important Findingsour data showed that the main floral visitors for C.communis at the two studied populations were small illegitimate bees rather than legitimate pollinators,accounting for 77.5 and 92.2%of total flower visits,respectively.Flower manipulations in C.communis demon-strated that the two types of brightly yellow stamens separately func-tioned as‘deceptive attraction’and‘feeding’functions.although the brown inconspicuous stamens of C.communis with the largest amount of fertile pollen had the potential function in offering pollen for cross pollination,the high ratio of illegitimate visitation by small bees significantly affected the dispersal and deposition of pollen from the pollinating anthers,and subsequently decreased the levels of outcrossing(tm=0.23-0.32)in wild populations.our work further confirmed that the size match between pollinators and the floral morp
文摘THE West saw The Hague Arbitral Tribunal＇s arbitration of the South China Sea dispute as an important crossroads in China＇s rise as a global power. The first misperception of the West is that China is rising - it is not rising, it has already risen, China is actually 10 steps ahead of the West in most cases, and Shanghai makes New York look like the old world.
